The present invention relates to the prevention of manipulations of microprocessor systems, in particular of engine-control devices for motor vehicles. Such devices are generally configured as microprocessor systems having a microprocessor, a program and main memory for the microprocessor and one or a plurality of interfaces for the communication with sensors and actuators on the engine. By manipulating the control program of the processor, it is possible to influence the behavior of the engine so as to achieve higher engine output, for example. Power-output limitations, which are required to prevent possibly harmful overload situations of the engine or which are mandated by law, may be circumvented in this manner. Consequently, there is a need for technology that makes unauthorized manipulations of such microprocessor systems impossible or at least makes them more complicated in a deterring manner.
One technique known and utilized for this purpose is the cementing of modules of such a microprocessor system. However, it has become apparent that no adhesive agent is available that is not able to be undone again in some manner. Another serious disadvantage of cementing is that it not only makes unauthorized manipulations more difficult, but repairs of the microprocessor system as well.